If you look in your handbooks..or Gregories Manuals you will find Ford suggest Penrite HPR 15 which is a 15W-50...quite suitable for the whole E-Series range of motors. Of course there is reasons to deviate from this, engine wear, kilometres, gas systems, worked engines and turbos.

just depends on the k's on your car as to what viscosity oil you use. I myself have an EB 5ltr with 165,000k's and I use Valvoline. But as I dont own an EF I couldn't really recommend a particular oil. Just as long as its not black & gold or home brand or something. Use a reputable brand and you wont be sorry.